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Acceptance Quality Limit (AQL): What is that?

Acceptance Quality Limit (AQL): What is that?



It is extremely time-consuming to check every single one of the ordered products. Therefore an international standard, the ISO 2859-1, was developed for picking samples. This standard was developed to choose a statistically representative number of samples. It is also used to define the limit between accepting an order and rejecting it. The tables used for this are called the Acceptance Quality Limit / Level (AQL) tables.
The limit has been described in the ISO 2859 as the worst quality level that’s acceptable. In practice, three types of defects are differentiated.

  • Minor defects: mistakes that most users will not mind, cosmetic defects.
  • Major defects: mistakes that an end user will not tolerate, functional defects.
  • Critical defects: completely unacceptable mistakes that can cause harm or might break a law.

According to the number of defects found, the inspection company will advise you to accept or reject an order.
An inspector has to choose a number of samples that is representative for the entire lot, and thus for the number of defects. The AQL tables form a statistical tool to find that number of samples.

Do you want to receive the Quality Control ISO 2859 AQL CalculatorPlease contact us.




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The work of an inspector


An inspector is a well-educated quality engineer and is specialized in a certain product category. A quality engineer, or inspector, is specialized in interpreting specifications and performing on site tests. He is trained to watch the details. Within a category an inspector is by no means a specialist in the sense that he knows everything about one single type of product. For example, an inspector specialized in the category of textile, is not a specialist in underwear. However, he has the training and experience to perform a professional inspection on underwear with the specifications of the client.

When he arrives in a factory, he starts by collecting the information about the supplier. Then he selects random samples from the finished products. First, the boxes to pick the samples from are chosen at random. Second, the inspector takes the number of samples out that the AQL tables give. Of course it is no problem if you wish to have your inspection performed at another inspection level (stricter or less strict).

During a standard inspection of these samples the following will always be checked:

  • The Acceptance Quality Limit (AQL)
  • The quantities
  • The product specifications
  • The labels and markings
  • The packaging

Depending on the product, the inspector will follow a checklist and conduct several tests (safety, functionality, etc.). If necessary, the checkpoints can be different than the original spec sheet. The inspector will check you products for the different types of defects that you have specified.

To perform an inspection correctly, the inspector carries several tools. These can include a camera, measuring tools, a Pantone (PMS) color book, a barcode scanner and special tape. Because the inspector has to travel to the factory, he cannot just bring an entire tool kit to every location. They do, however, carry the tools that are needed to perform the inspection correctly.

After the inspection, the inspector will put all of the findings into the protocol of the Quality Control company. This is the inspection report that you will receive by e-mail. The inspector can now go on to the next inspection.


Your local sourcing agent is not a reliable quality inspector!


When doing business in China, India or Vietnam you could use all the help you can get. It is a logical step to get a local sourcing agent that can help you with finding factories and ease the communication with suppliers. It is therefore not strange to think that an agent can also help with quality control. However, these local sourcing agents are not suitable for inspecting your products. They are not educated quality engineers, so they cannot perform a professional inspection. You will not receive an inspection report. How can you be certain that the inspection was actually performed? You cannot ensure that the sourcing agent was in your factory. Maybe he was busy or at the other side of the country. This accounts for a lot of risk, for which the agent cannot be held responsible.

Most agents will still claim to be able to perform professional quality control. It is possible that your agent is actually a real inspector. But it is normal that the sourcing agent receives a commission from the factory of which the importer is unaware. An agent gets a double pay: from the importer and from the factory. Therefore a sourcing agent will never reject an order, because the conflict of interest.

In short it is better to perform the quality control yourself or have it done by an independent Quality Control company.


Don’t wait until it’s too late


If you wait until your goods arrive in your country, there is nothing left that you can do. You have ordered the products in China, India or Vietnam from a supplier that you trust. You even provided a good list of specifications. That is why you just had the products shipped to your country. However, we see that it happens all too often that products turn out not to be suitable for the Western market: a big percentage of the order is defect. Unfortunately it is then too late to solve the problem.

In the Chinese, Indian and Vietnamese case it is not always possible to send defect products back. It is sometimes even forbidden by law! The government implemented this measure to prevent tax evasion. It is also very unlikely that the factory will redo your order for free or refund your money. The factory might offer a discount on the next order. But who wants to be tied to a next order with a manufacturer that delivers defect products? Only with a good contract that mentions product specifications in detail there is a small possibility that you will get your money back. But the odds are against you.

If the products can be reworked, you might want to do so in your own country. Labor and materials are a lot more expensive in that scenario. Even if you would ship the products to another low-cost country for example like Hong Kong for repair you still pay for shipment and labor.

That is why you are better off checking the quality during the production process at the factory, or having it checked for you. You can give tips and instructions to your supplier. This usually works best if you don’t pay the full amount before repairs and changes have been made by the factory. Moreover, this is how you show the workers and technicians who actually work on the product what is acceptable for you.

Such a quality control is a small investment if you compare it to a container full of useless products. Therefore most importers choose a Pre-Shipment Inspection (PSI) a couple of days before the goods are loaded into the container. Depending on the risk you would like to take, inspections can also be performed at other moments in the production process.


Spec Sheet: Your product specifications at a glance

Spec Sheet: Your product specifications at a glance

If you have found the right supplier, you decide whether the golden sample they sent you is good enough. This should be the example for the rest of the production. However, an approved golden sample is not good enough. To prevent problems and misunderstandings you make a list for the supplier wit hall the specifications of your product: a spec sheet. Not only can you use these specifications for the factory, but also as a reference for quality control. Inspectors can compare the state of the products with you specifications. That is why the information of a spec sheet is one of the most important things for an independent Quality Control company. It is the best way for the inspector to know which requirements he has to check, on top of the usual inspection.

Specifications need to cover the following aspects:

  • Quantity
  • Expected delivery
  • Boxes and packaging
  • Shape and cosmetics of the packaging
  • Size and weight
  • Labels, logos, tags and barcodes
  • Finishing, color and other visuals
  • Assembly and workmanship
  • Raw materials and parts

What we often see is that Western companies deliver their specifications to suppliers exactly the way they do to Western suppliers. That is where things go wrong. The important thing is the formulation of detailed specifications, so there is no room for interpretation. Be as specific as you can be, because the Chinese factory cannot just know your thoughts. Your methods for measuring and testing of those details should be mentioned as well.

Here are some more tips for a good spec sheet:

  • A list of definitions at the beginning of the spec sheet prevents misunderstandings of the specifications.
  • Always mention the standards you use: country-specific standards, Pantone colors (PMS), metric or imperial system, ISO standards, etcetera.
  • Specify the shipment conditions, so the supplier can take humidity and temperature into account.
  • Which deviations of your specifications are acceptable? And what will be the consequence if the supplier crosses that limit? Specify every defect.
  • Describe the Quality Control tests you want the factory to perform in detail.
  • Use clear language and avoid ambiguous references.

An introduction for importers

An introduction for importers

It’s a risky business to import products from developing countries. Not everybody is who he claims to be and dishonest suppliers will run off with your deposit. We know that most importers face two common issues. First, they often deal with low product quality. Asian suppliers often don’t understand that substandard products simply cannot be sold. Second, the production process is one of many delays.

For those reasons, big importers don’t have to think twice about Quality Control (QC) in low-cost countries. In case you import directly from China, India or Vietnam it is important that you know what Quality Control is and when you might need an inspection. This is an introduction into the world of Quality Control.

Before you start with inspections
It is important that you write down what you expect of a supplier. Let him know that you care about quality and that you will check it. Make your level of tolerance as clear as possible: what is a minor defect and what will not be accepted? This way, the factory will understand exactly what you expect. In case you choose an independent Quality Control company for quality control in your factory of choice, you can use all of the specifications for the inspection.

Check before shipment
If you wait until your goods arrive in your country, nothing can be changed. It is not possible to send defect products back. It is also very unlikely that the factory will redo the products for free or refund your money. That is why it is better to perform quality control during the production process. The supplier can use your tips and learns to understand your wishes. This is a small investment compared to a container full of useless products.

Don’t let your agent do it
Although a sourcing agent can help you along the way in searching for new factories and bridging a cultural gap, they cannot help you with quality control of your order. Most agents will get commissions from the factories for bringing new clients. That is why the verdict of the agent will never be negative. Also, agents are usually not trained to be a quality engineer or inspector. Therefore they will not convey inspections in a professional manner.

The work of an inspector
An inspector is a well-educated quality engineer and is specialized in a certain product category. Depending on the product, the inspector will go through a checklist. Think of quantity, appearance, conformity with your requirements and related functionality tests.

Picking samples
It takes a huge amount of time to check every single one of your ordered products. That is why there is an international standard, the ISO 2859-1, for picking samples. This standard is developed to choose a statistical representative number of samples. The tables used for this are called the Acceptance Quality Limit (AQL) tables.

The next step
Now you know a bit more about quality control and you can start with a reliable and independent Quality Control company like Quality Control China, Quality Control India & Quality Control Vietnam!


The use of quality control


ou might be wondering: ‘Why would I need quality control?’ The answer has to do with the risks that importers face. These risks emerge because of the many ‘transfer moments.’ These are the moments in which the products and components are moved from intermediary to intermediary before the end product is delivered to the client. It is like the game you used to play when you were young, where a sentence was whispered from person to person to end up as something completely different at the end of the line. If those transfer moments add up, you want to be sure that your supplier understood your wishes. And how closing are your agreements? Will you get what you have ordered? And will your client receive the promised products? There are many possible problems you could face.

Our experience, for instance, is that factories will make concessions at the end of the production or in a repeat order. The reason for this that the factory is trying to save money by using cheaper materials, to pay less attention to quality, to use cheaper (less qualified) personnel, and to rush the production.

The average personnel turnover in companies is quite high. If there are new employees working on your products again and again, problems with repeat orders will arise. What wasn’t a problem last time, might be a problem next time. There is no such thing as a learning curve, in which the production process goes smoother and smoother because the factory learns from its mistakes. Quite contrary, with every new order, new problems arise, because many workers see your product for the first time. Those kind of problems make that quality control is a must.

Yet another problem is the costs attached to the process of importing. Shipping goods to Europe is a costly activity. Shipping defective or wrong goods back to China, India or Vietnam is not even an option. But, you know your way and your business is successful, and in the course of the years you have found suppliers with which you are happy. Every now and then you travel to different countries and make your rounds. It is not strange to think that next shipments will be good if the last were. On top of that, inspecting quality yourself is costly and time consuming. You have to be at other places, traveling is exhausting, you would make long days at the factory, and the traveling expenses are high. Also, you would like to plan the trip in time, but for some reason your production is delayed. So you stop inspecting at a certain point.

Unless you have the time and expertise to check on your factory and inspect the goods before shipment, it is a wise move to have someone else perform the quality control of your products. Professional and independent inspectors from experienced Quality Control companies offer the solution.